The Evening Star MONDAY, AUGUST 25, 1873.

Evening Star, Issue 3280, 25 August 1873, Page 2

The Evening Star MONDAY, AUGUST 25, 1873.

Yery possibly most of our readers noticed that at the last meeting of the Otago Branch of the New Zealand Institute, Mr H. Skby read a paper “ On a Smokeless and Self-feeding Furnace for Lignites and other Fuels, and the Utilisation of the Waste-heat.” The paper is not only valuable as a contribution to science, but suggests a plan that seems likely to prove successful if adopted ; and if so, Mr Skey will have conferred a boon upon Otago more than equal to the discovery of a goldfield. We do not think that many would be able to follow him through the careful and minute-description'i he gave of the inductions through which he was led to adopt the particular arrangements for insuring complete combustion of the carbonaceous and gaseous elements of the coal ] nor could we do him justice by publishing his paper, without reproducing the diagram illustrating his plan. But we think the matter too important to be lost; sight of. But few heard the lecture: the Press has not given that prominence to the substance of it that its value deserves, and the result might have been its reproduction in the annual volume of “Transactions,” to lie upon the shelves of a few savans perhaps for years, or till accident had brought it under the notice of some quick-witted man of science, who might reproduce it as his own invention.

A few general observations on the matter may tend to show how deeply Otago is interested in it. We will not trouble our readers with statistics, but merely refer to their experience and memory by remarking that up to the present period, although Otago possesses immense stores of brown coal, it is well known that we have been obliged to import largely from Newcastle, notwithstanding the supply that can be poured into the market from Green Island, Shag Point, Kaitangata, and other places. The analysis of coal, given by Page, affords a clue to this seeming neglect of home production. Lignite, or brown coal, he tells us, contains from 56 to 70 parts of carbon, 3 to 7 parts of hydrogen, 13 to 27 of oxygen, 1 of nitrogen, and 1 to 13 of inorganic ash. Coal, on the other hand, contains from 70 to 92 parts of carbon, 2 to 6 of hydrogen, 1 to 8 of oxygen, 2 of nitrogen, and 3 to 14 of inorganic ash. As the carbon is the chief heat-producing constituent of coal, it is plain that our brown coals or lignites are less valuable than the true coal; yet the difference is not so wide as is generally assumed, nor is it nearly so great as the difference in price. Mr Skey says, “Judging from the evaporating power of fuels by the amount of their fixed carbon, their analyses show that I*s tons, that is U ton, of Green Islander Clutha coal should produce the same amount of steam as one ton of Newcastle coal.” Yet experience has shown that it does not, and Mr Skey has set himself to discover the reason why, and to devise a remedy. Two difficulties had to be overcome : carbon cannot burn without air, and through burning lignite or brown coal in an ordinary furnace, the “ bottom of the fire and fire-bars would soon be covered with an accumulation of ash and small fuel” which would prevent the passage of air through it. Instead, therefore, of burning with a .clear bright flame, it would smoulder; and should a remedy be attempted by stirring, apd even when adding fuel, waste would be caused by a portion of the burning mass being broken and falling through the bars. The object to be attained, then, is to form a furnace in which these difljculties can be overcome ; in which every heat-producing constituent shall be burnt, no heat wasted in the process, nor any loss of substance be caused .through stirring, j By a very ingenious application of the : principle of the hot blast and doing £Way with fire bars, we think Mr Skey has' succeeded, and that although his plan has thus far .oply reference to marine, railway, and manufacturing processes, were it confined to those alone i it is well worthy the earnest investigation of consumers and suppliers of coal, j He proposes to consume the smoke and get rid of the ash, and we see no reason why a modification of the plan might not be adapted to household purposes. We have long been of opinion that much improvement may be made in our mode of heating houses and cooking-stoves. We much. Begrudge the share that our fires claim of the scanty supply of fresh air architects admit into onr sitting-rooms, for we are fully of opinion that many serious diseases are traceable to this cauqc ; but when to the abstraction of oxygen is the supply of sulphurous smoke from partially consumed coal or lignite, the evil is immeasurably aggravated. Page says of lignites : “They burn with much smoke and dull flame ; are poorer in carbon or coke than common coal ; give much less heat; and leave, in general, a large residuum of earthy ashes." By Mr Skey’s plan thera is no smoke; great heat is obtained, because of perfect and rapid combustion ; and the 'residuum is either got rid of altogether, |

or, after being dispersed so as not to interfere with the flame, is compactly gathered into one place from which it can be easily removed. So important in its commercial, social, Provincial, and Colonial aspects is this subject, that we trust steps will be taken to further investigate it. Mr Skey deserves the thanks of the community for directing attention to it.